1. Field of the Invention
This invention relates to apparatus for removing stakes which are deeply embedded in the ground or in asphalt pavement. More particularly, the invention relates to a stake pulling apparatus for removing tent and awning stakes from the ground or from asphalt paving and underlying terrain, under circumstances where the stakes are deeply embedded in the ground and/or asphalt paving. The stake pulling apparatus of this invention is characterized by an upward-standing box-frame or tubular member which serves as a reservoir for hydraulic fluid, a bifurcated base plate welded or otherwise attached to the frame for supporting the frame in upright position and a hydraulic cylinder pivotally attached to the frame and adapted for positioning over a stake to be removed from the ground or from the asphalt paving. The apparatus is maneuvered to locate the stake in the slot provided in the base plate and a hydraulic pump, pump motor and control system are provided on the frame for controlling the flow of hydraulic fluid to the hydraulic cylinder and operation of the cylinder piston responsive to operation of the controls.
One of the problems realized in the erection of tents, canopies and other temporary structures which are secured in position by stakes, ropes and cables is that of removing the deeply embedded stakes from ground or asphalt surfaces. Under circumstances where the tent, canopy or other structure to be erected is relatively large, the stakes must be long and deeply embedded in the ground or asphalt and are therefore very difficult to remove. Because of the difficulty of removing these stakes, in many cases, the stakes must be left embedded in the ground and in some instances, are simply driven further into the ground or asphalt flush with the surface of the ground or asphalt after use, to prevent injury. In the case of large canopies such as circus tents, these stakes may be steel spikes 2 to 4 feet in length and 1 to 1/2 inches in diameter and may be driven into the ground or asphalt to within about 5 or 6 inches of the top end thereof. The difficulty of removing such stakes from the ground or asphalt paving after striking the tent can be readily appreciated. Since many such tent stakes or spikes are necessary to secure a circus tent or other large canopy, failure to remove these stakes after the performance or event is completed results in a considerable loss of revenue.
2. Description of the Prior Art
Various devices are known in the art for removing embedded railroad spikes from cross ties in railroad maintenance operations. Typical of these machines is the "spike pulling machine" disclosed in U.S. Pat. No. 2,691,505, dated Oct. 12, 1954, to S. R. Hursh. The spike pulling machine detailed in this patent includes a compact, light-weight and readily portable machine for withdrawing spikes from objects such as railroad ties, which device is fluid-operated and is braced against a track rail to effect withdrawal of the spikes from the ties of the track bed. The spike pulling machine includes a base, a rigid frame slidably mounted on the base, a grapple suspended from the frame and oriented in position to engage and disengage a spike to be pulled, a jack element located on the base for sliding the rigid frame up and down relative to the base, operating means for operating the jack element, control means for activating and inactivating the operating means and limit means connected to the jack element and operative in response to the movement of the frame for operating the control means and thereby inactivating the jack-operating element when the frame and base reach predetermined positions relative to one another. U.S. Pat. No. 2,732,173, dated Jan. 24, 1956, to S. R. Hursh, discloses a "Spike Pulling Apparatus". The device detailed in this patent includes a truck provided with wheels constructed to move along a railroad track with additional adjustable wheels normally supported above the first set of wheels. The upper adjustable wheels are movable up and down to and from a lower, ground-engaging position and an elongated body member is pivoted to the track for swinging movement in an arc above the track at an angle extending upwardly with respect to the horizontal. The body member includes two body portions pivoted together by means of a substantially universal pivot, a spikepulling grapple carried by the body member and spaced along the body member from the truck, power means supported by the truck and flexible connecting means extending along the body member for connecting the power means to the grapple and operating the grapple. A "Pneumatic Spike Extractor" is disclosed in U.S. Pat. No. 2,735,649, dated Feb. 21, 1956, to S. A. Swallert. The extractor device detailed in this patent includes a pair of jaws which are pivotably mounted on the outer end of a rod fixed to a pressure-operated piston. The piston is enclosed in a cylinder provided with devices for alternately connecting the chambers on both sides of the piston with a source of pressurized air. A locking member is arranged to lock the jaws in a position gripping the head of a nail when the piston rod is in an outer configuration. U.S. Pat. No. 2,797,889, dated July 2, 1957, to H. H. Talboys, discloses a "Hydraulic Spike Puller". The spike pulling implement detailed in this patent includes an elongated frame, a spike-gripping claw mounted for reciprocating movement at one end of the frame, the frame also including a portion adapted to bear against a surface external to an embedded spike, along with means for reciprocating the claw with respect to the frame to remove a spike from an embedded position. An opening is provided on one side of the frame adjacent the claw, the opening being generally co-extensive with the range of movement of the claw and a resilient arm is mounted on the other side of the frame for contact with the spike engaged by the claw and forcing the spike through the opening. U.S. Pat. No. 2,846,187, dated Aug. 5, 1958, to I. Sublett, et al, details a "Hydraulic Spike Pulling Apparatus". The device disclosed in this patent includes a movable, hydraulically-operated element for effecting movement of an object upon actuation of the element in one direction and a hydraulic pressure accumulator operatively connected to the element, with the hydraulic pump communicating with and supplying pressure to the element and the accumulator. The pressure provided by the pump effects initial actuation of the element in the one direction and the pressure accumulated within the accumulator supplements that of the pump in effecting final actuation of the element in the same direction. A "Machine For Pulling Pins" is disclosed in U.S. Pat. No. 2,911,190, dated Nov. 3, 1959, to F. Creason. This patent details a pin-extracting mechanism for removing forms located at the sides of concrete slabs in road and similar construction, the machine including a mobile frame adapted to be moved upon the slab alongside the form. A first fluid pressure-actuated mechanism is located on the frame for engaging and pulling the pins and a separate fluid pressure-actuating mechanism is also provided on the frame for engaging and applying a downward pressure on the form during actuation of the pin pulling means. A mechanism is also provided on the frame for manually controlling the fluid pressure to and from the fluid pressure-actuated mechanisms.
It is an object of this invention to provide a stake pulling apparatus which is designed to quickly, easily and efficiently remove wood and metal stakes driven into bare ground or asphalt-covered terrain.
Another object of the invention is to provide a new and improved stake pulling apparatus which is portable in construction and is capable of being located above a stake to be removed from the ground or from asphalt paving, which apparatus can then be attached to the stake and operated to quickly and efficiently remove the stake from the ground or asphalt.
Still another object of this invention is to provide a new and improved embedded stake pulling apparatus which is characterized by a hydraulic cylinder pivotally mounted on an upright frame fitted with an engine, a hydraulic motor and a control system for operating the hydraulic cylinder and removing stakes from the ground.
Yet another object of this invention is to provide a stake pulling apparatus which is portable in construction and includes a frame provided with a hydraulic fluid reservoir, a hydraulic cylinder pivotally attached to the frame, a hydraulic motor mounted on the frame and provided in fluid communication with the hydraulic cylinder and the reservoir, a two-cycle engine mounted on the frame for operating the hydraulic motor and a control system for selectively applying hydraulic pressure to the hydraulic cylinder and removing a stake embedded in the ground or asphalt paving and located beneath the hydraulic cylinder.
A still further object of this invention is to provide a stake pulling apparatus for removing stakes which are deeply embedded in the ground or in asphalt paving and in underlying terrain, which apparatus includes an upright box-frame or tubing designed to contain a quantity of hydraulic fluid and a base welded to the box-frame or tubing and having a slot for receiving an embedded stake. A hydraulic pump is mounted on the frame, along with a hydraulic cylinder, an engine adapted for operating the hydraulic pump and a control system for controlling the flow of hydraulic fluid from the box-frame or tubing to the hydraulic cylinder and removing the stake from the ground or asphalt responsive to retraction of the hydraulic cylinder piston.